Get the "Tags" property in C#

Question

Hello

Can anyone please tell me how I can get the value of the "Tags" column as shown in Windows Explorer using C#?

e.g.

Very simple Console app using FileInfo but there's no attribute for Tags" as far as I can see.

Thanks in advance.

Answer 1

this a windows only feature called extended properties. you will need to the system shell:

https://learn.microsoft.com/en-us/windows/win32/shell/shellfolderitem-extendedproperty?redirectedfrom=MSDN

Answer 2

You can use IPropertyStore

For example :

        string sFileName = @"E:\test.jpg";  
        IPropertyStore pPropertyStore = null;  
        Guid PropertyStoreGuid = typeof(IPropertyStore).GUID;  
        HRESULT hr = SHGetPropertyStoreFromParsingName(sFileName, IntPtr.Zero, GETPROPERTYSTOREFLAGS.GPS_READWRITE, ref PropertyStoreGuid, out pPropertyStore);  
        if (hr == HRESULT.S_OK)  
        {  
            var pv = new PROPVARIANT();  
            hr = pPropertyStore.GetValue(PKEY_Keywords, out pv);  
            if (pv.varType == (ushort)(VARENUM.VT_VECTOR | VARENUM.VT_LPWSTR))  
            {  
                for (uint i=0; i<pv.ca.cElems; i++)  
                {    
                    IntPtr pString = Marshal.ReadIntPtr(pv.ca.pElems, (int) i * IntPtr.Size);  
                    string sKeyWord = Marshal.PtrToStringUni(pString);  
                    Marshal.FreeCoTaskMem(pString);  
                    Console.WriteLine("Tag({0}) : {1}", i, sKeyWord);  
                }  
            }  
            Marshal.ReleaseComObject(pPropertyStore);  
        }  

with declarations :

    public enum HRESULT : int  
    {  
        S_OK = 0,  
        S_FALSE = 1,  
        E_NOINTERFACE = unchecked((int)0x80004002),  
        E_NOTIMPL = unchecked((int)0x80004001),  
        E_FAIL = unchecked((int)0x80004005),  
        E_UNEXPECTED = unchecked((int)0x8000FFFFL)  
    }  

    [DllImport("Shell32.dll", SetLastError = true, CharSet = CharSet.Unicode)]  
    public static extern HRESULT SHGetPropertyStoreFromParsingName(string pszPath, IntPtr pbc, GETPROPERTYSTOREFLAGS flags, ref Guid iid, [MarshalAs(UnmanagedType.Interface)] out IPropertyStore propertyStore);  

    public enum GETPROPERTYSTOREFLAGS  
    {  
        GPS_DEFAULT = 0,  
        GPS_HANDLERPROPERTIESONLY = 0x1,  
        GPS_READWRITE = 0x2,  
        GPS_TEMPORARY = 0x4,  
        GPS_FASTPROPERTIESONLY = 0x8,  
        GPS_OPENSLOWITEM = 0x10,  
        GPS_DELAYCREATION = 0x20,  
        GPS_BESTEFFORT = 0x40,  
        GPS_NO_OPLOCK = 0x80,  
        GPS_PREFERQUERYPROPERTIES = 0x100,  
        GPS_EXTRINSICPROPERTIES = 0x200,  
        GPS_EXTRINSICPROPERTIESONLY = 0x400,  
        GPS_VOLATILEPROPERTIES = 0x800,  
        GPS_VOLATILEPROPERTIESONLY = 0x1000,  
        GPS_MASK_VALID = 0x1FFF  
    }  

    [ComImport, Guid("886D8EEB-8CF2-4446-8D02-CDBA1DBDCF99"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]  
    public interface IPropertyStore  
    {  
        HRESULT GetCount([Out] out uint propertyCount);  
        HRESULT GetAt([In] uint propertyIndex, [Out, MarshalAs(UnmanagedType.Struct)] out PROPERTYKEY key);  
        HRESULT GetValue([In, MarshalAs(UnmanagedType.Struct)] ref PROPERTYKEY key, [Out, MarshalAs(UnmanagedType.Struct)] out PROPVARIANT pv);  
        HRESULT SetValue([In, MarshalAs(UnmanagedType.Struct)] ref PROPERTYKEY key, [In, MarshalAs(UnmanagedType.Struct)] ref PROPVARIANT pv);  
        HRESULT Commit();  
    }  

    [StructLayout(LayoutKind.Sequential, Pack = 4)]  
    public struct PROPERTYKEY  
    {  
        private readonly Guid _fmtid;  
        private readonly uint _pid;  

        public PROPERTYKEY(Guid fmtid, uint pid)  
        {  
            _fmtid = fmtid;  
            _pid = pid;  
        }    
    }  

    public static readonly PROPERTYKEY PKEY_Title = new PROPERTYKEY(new Guid("F29F85E0-4FF9-1068-AB91-08002B27B3D9"), 2);  
    public static readonly PROPERTYKEY PKEY_Keywords = new PROPERTYKEY(new Guid("F29F85E0-4FF9-1068-AB91-08002B27B3D9"), 5);  
 
    [StructLayout(LayoutKind.Sequential, Pack = 0)]  
    public struct PROPARRAY  
    {  
        public UInt32 cElems;  
        public IntPtr pElems;  
    }  

    [StructLayout(LayoutKind.Explicit, Pack = 1)]  
    public struct PROPVARIANT  
    {  
        [FieldOffset(0)]  
        public ushort varType;  
        [FieldOffset(2)]  
        public ushort wReserved1;  
        [FieldOffset(4)]  
        public ushort wReserved2;  
        [FieldOffset(6)]  
        public ushort wReserved3;  

        [FieldOffset(8)]  
        public byte bVal;  
        [FieldOffset(8)]  
        public sbyte cVal;  
        [FieldOffset(8)]  
        public ushort uiVal;  
        [FieldOffset(8)]  
        public short iVal;  
        [FieldOffset(8)]  
        public UInt32 uintVal;  
        [FieldOffset(8)]  
        public Int32 intVal;  
        [FieldOffset(8)]  
        public UInt64 ulVal;  
        [FieldOffset(8)]  
        public Int64 lVal;  
        [FieldOffset(8)]  
        public float fltVal;  
        [FieldOffset(8)]  
        public double dblVal;  
        [FieldOffset(8)]  
        public short boolVal;  
        [FieldOffset(8)]  
        public IntPtr pclsidVal; // GUID ID pointer  
        [FieldOffset(8)]  
        public IntPtr pszVal; // Ansi string pointer  
        [FieldOffset(8)]  
        public IntPtr pwszVal; // Unicode string pointer  
        [FieldOffset(8)]  
        public IntPtr punkVal; // punkVal (interface pointer)  
        [FieldOffset(8)]  
        public PROPARRAY ca;  
        [FieldOffset(8)]  
        public System.Runtime.InteropServices.ComTypes.FILETIME filetime;  
    }  

    public enum VARENUM  
    {  
        VT_EMPTY = 0,  
        VT_NULL = 1,  
        VT_I2 = 2,  
        VT_I4 = 3,  
        VT_R4 = 4,  
        VT_R8 = 5,  
        VT_CY = 6,  
        VT_DATE = 7,  
        VT_BSTR = 8,  
        VT_DISPATCH = 9,  
        VT_ERROR = 10,  
        VT_BOOL = 11,  
        VT_VARIANT = 12,  
        VT_UNKNOWN = 13,  
        VT_DECIMAL = 14,  
        VT_I1 = 16,  
        VT_UI1 = 17,  
        VT_UI2 = 18,  
        VT_UI4 = 19,  
        VT_I8 = 20,  
        VT_UI8 = 21,  
        VT_INT = 22,  
        VT_UINT = 23,  
        VT_VOID = 24,  
        VT_HRESULT = 25,  
        VT_PTR = 26,  
        VT_SAFEARRAY = 27,  
        VT_CARRAY = 28,  
        VT_USERDEFINED = 29,  
        VT_LPSTR = 30,  
        VT_LPWSTR = 31,  
        VT_RECORD = 36,  
        VT_INT_PTR = 37,  
        VT_UINT_PTR = 38,  
        VT_FILETIME = 64,  
        VT_BLOB = 65,  
        VT_STREAM = 66,  
        VT_STORAGE = 67,  
        VT_STREAMED_OBJECT = 68,  
        VT_STORED_OBJECT = 69,  
        VT_BLOB_OBJECT = 70,  
        VT_CF = 71,  
        VT_CLSID = 72,  
        VT_VERSIONED_STREAM = 73,  
        VT_BSTR_BLOB = 0xfff,  
        VT_VECTOR = 0x1000,  
        VT_ARRAY = 0x2000,  
        VT_BYREF = 0x4000,  
        VT_RESERVED = 0x8000,  
        VT_ILLEGAL = 0xffff,  
        VT_ILLEGALMASKED = 0xfff,  
        VT_TYPEMASK = 0xfff  
    };